连续变量量子密钥分发的理论和实验研究

发布时间：2018-01-29 15:04

本文关键词： 量子密钥分发连续变量光场轨道角动量非线性光学纠缠　出处：《国防科学技术大学》2014年博士论文　论文类型：学位论文

【摘要】：连续变量量子密钥分发是量子信息中一个重要的研究方向,它可以实现无条件安全的保密通信。这种方案充分利用了光场的边带资源,并且具有良好的噪声抑制能力。本博士论文总结了作者博士期间在这个领域所做的主要工作,分为以下几点:1.针对实际系统激光器中存在噪声,并且调制器不能进行理想调制的情况,分析了光源噪声对安全性的影响,给出了安全码率的下界。2.搭建了自由空间的四态协议连续变量量子密钥分发演示验证系统,同时采用无切换方案,提高了系统的通信速率。3.搭建了基于光纤的准连续光连续变量量子密钥分发系统,通过时分复用和偏振复用抑制信道串扰,同时采用了无切换方案和宽带调制提高了系统的通信速率。4.为了实现连续变量量子密钥分发中对光场不同自由度的复用,对光场轨道角动量进行了研究,在实验上制备了具有超高轨道角动量量子数的光场。5.针对连续变量量子中继中需要Schr(?)dinger猫态作为光源的问题,提出了利用非线性纠缠得到大小连续可调的猫态的方案。同时为了在实验上观察到这种微弱的非线性效应进行了方形微型光学谐振腔的研究。6.为了将连续变量量子密钥分发拓展到可见光波段,研制了高功率紫外连续波激光器,搭建了绿光光学参量放大器,实现了绿光的放大和反放大。
[Abstract]:Continuous variable quantum key distribution is an important research direction in quantum information. It can realize unconditionally secure secure communication. This scheme makes full use of the sideband resources of light field. And has good noise suppression ability. This doctoral thesis summarizes the main work done in this field during the doctoral period, which can be divided into the following points: 1. Aiming at the existence of noise in the actual laser system. And the modulator can not be ideal modulation, the impact of light source noise on the security is analyzed. The lower bound of the secure code rate is given. 2. A four-state protocol quantum key distribution demonstration and verification system with continuous variables in free space is built, and a no-switching scheme is adopted at the same time. The communication rate of the system is improved. 3. A quasi continuous optical variable quantum key distribution system based on optical fiber is built to suppress channel crosstalk through time division multiplexing (TDM) and polarization multiplexing (polarization multiplexing). At the same time, no switching scheme and broadband modulation are used to improve the communication rate of the system. In order to realize the multiplexing of different degrees of freedom in the continuous variable quantum key distribution, the orbital angular momentum of the optical field is studied. The light field with ultra-high orbital angular momentum quantum number has been prepared experimentally. The problem of dinger cat state as light source. In this paper, we propose a scheme to obtain the cat state with continuously adjustable size by nonlinear entanglement. In order to observe this weak nonlinear effect experimentally, the square micro optical resonator is studied. 6. Quantum key distribution is extended to visible light band. A high power ultraviolet CW laser is developed and a green optical parametric amplifier is built to amplify and reverse amplify the green light.
【学位授予单位】：国防科学技术大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN918.4

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